Adjustable caster construction



' Sept. 2, 1941. c. R. NALLE ADJUSTABLE CASTER. CONSTRUCTION FiIed April19, 1940 Patented Sept. 2, 1941 UNITED STATES PATENT OFFICE y 2,254,973ADJUSTABLE CASTER CONSTRUCTION Charles R. Nalle, Philadelphia, Pa.Application April 19, 1940, Serial No. 330,601

(01. 11s- 19) y v V 2 Claims.

This invention .relates to furniture casters, glides, or the like; and,more particularly, to a.v novel form of adjustable caster. Heretofore,many attempts have been made to produce economically an adjustablefurniture support, but all such attempts with which I am familiar leavemuch to be desired.

In a glider or caster of this type, it is necessary that a threadedsocket be provided for directv attachment to the furniture, such socketbeing secured to the furniture either, as in the case of woodenfurniture, by placing the socket in a bore in the leg of the furniture;or, in the p case of metallic furniture, by threading the socket intothe metal of the furniture leg, or otherwise securing the same thereto.Y

An important object of the present invention is the provision of anadjustable caster having a socket formed from a die casting having aclosed upper end and interiorly threaded, thereby providing an extremelysolid connection between the socket and stem. In accordance with myinvention, this socket has its upper end closed so that there is nopossibility of fine boringsentering the socket and interfering withproper ad- .iustment Another object of the invention is the provision ina construction of this character of an arrangement which insures againstjamming of the threaded connection when the stem shall have been enteredin the socket to the limit.

Another-object of the invention is the provision of a structure of thischaracter which, due to its formation, will continue in solid engagementand rigid relation to the legs of wooden furniture.

These and other objects I attain by the construction shown in theaccompanying drawing wherein, for the purpose of illustration, I haveshown a preferred embodiment of my invention and wherein:

Fig. l is a vertical sectional view showing a glide, constructed inaccordance with my invention, applied to the leg of metallic furniture;

Fig. 2 is a vertical sectional view through the socket of Fig. l; y

Fig. 3 is a vertical sectional view illustrating a glide applied to theleg of wooden furniture;

Fig. 4 is a side elevation of the socket of Fig. 3;

Fig. 5 illustrates a slightly modified method of constructing thesockets; Aand Fig, 6 is a sectional view illustrating an im- .provedmethod of formation of the glide'.

Referring now to the drawing, the numeral I0 generally designates athreaded shank of a caster or glide; and Il, a socket for the receptionof said shank. In accordance withv my invention, this socket is die-cast andl then interiorly threaded as at i2. The socket has its upperend closed as at I3 and this closed upper end is provided with adependingcentrally located conical projection i4 which is adapted toabut the upper end of the shank I0 when the same has been fully engagedin the socket and limit the movement thereof. Due to the fact that thearea of the tip of this conical portion is extremely small, vbut littlefriction will be exerted on the upper end of the shank I0 sothat'theshank may be readily Withdrawn.

It is, obviously, impractical to extend the threading of the socketentirely to the upper end thereoffdue both to the construction of thetap and` to the fact that 'the cuttings tend to collect in the bore inadvance of the tap so that a complete threading, disregarding thelimitations of the tap, could only be obtained by one or morewithdrawals of the tap to permit these cuttings to escape. This I haveovercome to eacertain extent by forming in the upper end at 'the sidewall of the socket a small opening I5 through which air may be forcedduring the tapping operation to cause these cuttings to be elected. Inorder to provide for maximum engagement of the shank I0 in the socketand at the same time to enable the upper end of the stem to'engage theprojecl tion, this shank is formd as a dog point'screw,

the unthreaded reduced upper end portion therel I of being indicated atI6.

Where a socket of this type is to be used with metallic furniture, the`lower portion thereof is somewhat increased in diameter at its lowerend and exteriorly threaded as atl I1, and the lower end thereof isformed with a polygonal flange Il which may be engaged by a wrench andwhich will limit the movement of the shank into an opening of thefurniture socket 19. The threaded portion I1 may be either threadeddirectly into the metal of the socket, or of the furniture itself, or anut 20 may be utilized for clamping the socket in position, or both maybe employed.

For wooden furniture, a socket of the type u shown in Figures 3 and 4 isemployed, this socket in the furniture leg is made of such diameter thatthe socket will ilt'snugly therein, and the 'socket is driven into theopening to an extent such that the teeth 22 embed themselves in the 'Ihebore 23 f lower end of the furniture leg and thus securely hold thesocket against rotation. In this operation the opening l' serves topermit escape of air trapped in the bore above the socket and thusfacilitate its insertion. Due to its considerable length and to the factthat it is suiciently solid that it may be very forcibly driven into thebore, the socket has` an extremely rm engagement with the furniture leg.This engagement is enhanced and preserved by the use of the relativelylarge, well-spaced teeth on the flange of the socket, since these teethnot only prevent rotation of the socket but likewise, through their gripin the wood of the leg,` prevent any side movement of the socket.

In Figure 5, I have shown a slightly modified construction in which theupper end of the socket is closed, not by an integrally cast head, butby an insertedplug 13a bearing the conical tip Ha.

In constructing a glide in accordance with my invention, I preferablyprovide the lower end of the screw with a rounded head 24, having foundthat where a head is to be embedded in Bakelite or some similarcomposition, indicated at 25, the rounding of the head serves to preventcracking of the composition which occurs where flat heads are employed.The shank may be secured against rotation by providing this head with ascrew slot 26, or with a squared neck portion 2l, or both.

Since the construction illustrated is capable of some modificationwithout departing from the spirit of my invention, I do not wish to beunderstood as limiting myself to the particular construction orapplications of this construction herein disclosed, except ashereinafter claimed.

I claim:

. 1. In an adjustable furniture caster or glide, a threaded stem havinga ground-engaging support at its lower end, a tubular socket member foradjustably receiving said stem and adapted for insertion in a bore inthe leg of an article of furniture, said socket member being interiorlythreaded over a portion of its length for engagement with the stem andhaving its upper end i tion and the upper end of the stem owing to theextremely small area of the lower end of said projection which canengage the upper end surface of said stem, whereby binding engagementbetween the threaded portions of the stem and socket member iseffectively prevented.

2. In an adjustable furniture caster or glide, a threaded stem having aground-engaging support at its lower end, a tubular socket member foradjustably receiving said stem and adapted for insertion in a bore inthe leg of an article of furniture, said socket member being interiorlythreaded over a portion of its length for engagement with the stem andhaving its upper end closed, and means for limiting the upwardadjustment of said stem within said socket member and for effectivelypreventing binding between said elements, said means comprising aprojection on the upper end of one of said elements having an end ofextremely small area arranged for engagement by the upper end of theother element, whereby the possible frictional engagement between saidelements is reduced to a minimum, and binding engagement between thethreaded portions of said elements is effectively prevented.

CHARLES R. NALLE.

